Research On Deceptive Jamming Technology Based On SAR Target Characteristics

With the development of synthetic aperture radar(SAR)technology,the resolution of SAR image is getting higher and higher,and the SAR image contains more and more information.In electronic warfare,aircraft and spy satellites with SAR imaging system are effective and important means to acquire enemy information.The interference and countermeasures of SAR are the focus of research in various countries.As an important way of interference,spoofing interference is a subject that needs in-depth research and has far-reaching influence.At present,the spoofing jamming technique of SAR is generally to generate some targets with certain similarity,but the effect of these false targets on the recognition is very fuzzy,and there is very little to verify with the recognition algorithm.In addition,because there is no systematic theoretical support,the research on interference implementation appears to be blind.Starting from the analysis of SAR image target characteristics,this paper studies spoofing interference method and explores the realization technology of interference.The main research work and innovation are as follows:1.The imaging mechanism of SAR is introduced,and the reconstruction process of target backscatter coefficient by SAR imaging system is analyzed.Generally,only similar objects have similar scattering coefficients,and then they show similar scattering distributions in SAR images.It shows that different targets are separable in SAR images,which provides a possibility for target recognition in SAR images.2.The principle of spoofing jamming technology is analyzed,and the possibility of fine spoofing jamming is proved by simulation.In essence,SAR spoofing jamming is to add jamming signal to the echo of the target.Through theoretical analysis,it is found that as long as the delay time and phase modulation of the jamming signal are well controlled,false targets can be generated at different positions.Finally,the feasibility of generating spoofing false target in the designated location is verified by experimental simulation.3.Apply convolutional neural network to SAR image processing research.Firstly,the basic principle and important characteristics of convolutional neural network are introduced,and then DCGAN is introduced.DCGAN network is used to generate SAR image target samples.The experiment proves that the generated SAR image and the original image have a high degree of similarity in statistics and target characteristics.In addition,an improved network with three convolution layers and three pooling layers is built as SAR target recognizer to verify the effect of spoofing.4.A deceptive jamming technique based on shape change of SAR target is studied,which has good effect and gives the flow chart of algorithm implementation.The goal of the experimental design is to disguise an armored vehicle as a tank vehicle,and it is found that better results can be obtained by processing in the image domain,and the geometric features of the target also change greatly.The theoretical analysis of interference modulation is given and the simulation verification is given.In addition,according to the scattering distribution of the target,a spoofing jamming technique based on the change of scattering distribution is studied.